// src/services/record-cache.js

const cache = new Map();
const listeners = new Map();

function notify(key, data) {
  const keyListeners = listeners.get(key);
  if (keyListeners) {
    for (const callback of keyListeners) {
      callback(data);
    }
  }
}

export const recordCache = {
  /**
   * Get a cached record by key
   * @param {string} key - Cache key (typically AT Protocol URI, or "profile:{handle}" for profiles)
   * @returns {object|undefined} Cached record or undefined
   */
  get(key) {
    return cache.get(key);
  },

  /**
   * Set/merge record data. Dispatches update event.
   * @param {string} key - Cache key (typically AT Protocol URI, or "profile:{handle}" for profiles)
   * @param {object} data - Partial or full record data
   */
  set(key, data) {
    const existing = cache.get(key) || {};
    const merged = { ...existing, ...data };
    cache.set(key, merged);
    notify(key, merged);
  },

  /**
   * Check if a key is cached
   * @param {string} key - Cache key (typically AT Protocol URI, or "profile:{handle}" for profiles)
   * @returns {boolean}
   */
  has(key) {
    return cache.has(key);
  },

  /**
   * Subscribe to changes for a specific key
   * @param {string} key - Cache key (typically AT Protocol URI, or "profile:{handle}" for profiles)
   * @param {function} callback - Called with updated data
   */
  subscribe(key, callback) {
    if (!listeners.has(key)) {
      listeners.set(key, new Set());
    }
    listeners.get(key).add(callback);
  },

  /**
   * Unsubscribe from changes
   * @param {string} key - Cache key (typically AT Protocol URI, or "profile:{handle}" for profiles)
   * @param {function} callback - The callback to remove
   */
  unsubscribe(key, callback) {
    const keyListeners = listeners.get(key);
    if (keyListeners) {
      keyListeners.delete(callback);
      if (keyListeners.size === 0) {
        listeners.delete(key);
      }
    }
  },

  /**
   * Clear all cached data and subscriptions (useful for logout)
   */
  clear() {
    cache.clear();
    listeners.clear();
  }
};